German published patent application DE-OS-3 703 511 describes a mirror cassette on which the hinge between the flap and the cassette is provided by stubs mounted to slide axially in a bore formed on the flap and co-operating with cavities constituting bearings provided in corresponding positions on the cassette. The flap is locked in the open position and in the closed position by means of co-operating projections formed concentrically with the pivot axis, one of them being fixed and formed on the cassette while the other is formed on the outer end of the corresponding stub. A compression spring is provided so that the projection on the stub is firmly engaged with the corresponding projection on the cavity.
The drawback of this prior cassette is that its various parts are difficult to make and assemble. The bores of the flap and the cavities constituting bearings require retractable cores to be provided in the molds used for manufacturing the cassette and the flap, thereby increasing the cost of the molds and reducing manufacturing throughput. In addition, it turns out to be particularly difficult and laborious to incorporate the compression spring since it must be mounted in the compressed state.
French patent application No. 88 04 457 describes another cassette in which the hinge stubs are formed on the side edges of the cassette and co-operate with corresponding cavities provided on the edges of the flap.
This cassette suffers from the drawbacks firstly that the mold for making the flap requires retractable cores in order to form the bearing-forming cavities, and secondly when the flap is mounted on the housing, one of the stubs needs to be inserted in the corresponding cavity, after which the flap needs to be resiliently deformed so as to force the other stud into its cavity, and this can lead to breakages, either of the flap, or else of a stub. The smaller and stiffer the flap, the greater the difficulty encountered during assembly.
A mirror cassette is commercially available in which the flap includes cavities forming bearings and the cassette has stubs which co-operate with the bearings, and in which the moving stop element for the flap is constituted by a V-shaped tab provided on the edge of the flap adjacent to the alignment of the cavities, and the fixed stop element on the cassette is constituted by a spring blade applying a force on the flap urging it towards the front face of the housing.
This prior cassette suffers from the same drawbacks as the cassette described in French patent application No. 88 04 547.
The object of the present invention is to mitigate these drawbacks and to provide a mirror cassette of the type mentioned above which is firstly easy to assemble and which secondly eliminates the need to provide retractable cores in the molds used for manufacturing the cassette housing and/or its cover, thereby reducing the cost of the molds and increasing the rate at which the molded parts can be manufactured.